Identification of SPAG9 as a novel JAK2 fusion partner gene in pediatric acute lymphoblastic leukemia with t(9;17)(p24;q21)

We have identified a novel SPAG9‐JAK2 fusion in a B‐cell precursor acute lymphoblastic leukemia (ALL) with t(9;17)(p24;q21) and a poor outcome, using paired‐end transcriptome sequencing. Homozygous and hemizygous deletionsof CDKN2A/2B , and hemizygous deletions of PAX5 , BTG1 , CDK6 , ADARB2 , and IKZF1 were also identified by multiple ligation‐dependent probe amplification and single nucleotide polymorphism array analyses. Having both a tyrosine kinase‐activating rearrangement and genomic lesions affecting lymphoid transcription factors suggested that the leukemia was of the Philadelphia chromosome (Ph)/ BCR‐ABL1 ‐like ALL subtype and that JAK2 inhibitors might be able to overcome this aggressive ALL with SPAG9‐JAK2 . © 2015 Wiley Periodicals, Inc.